The present invention relates generally to software defined networking, and more particularly to utilizing a controller for preprogramming a network before removal of a network switch.
In current software defined networking (SDN) architecture, when a network switch gets upgraded, the SDN controller for the network is typically unaware. Therefore, when the network switch is removed and disconnected from the controller, the controller treats it like a TCP connection has gone down due to possible reasons such as, the network being down or the power being switched off. In such a scenario, the controller removes the switch from its forwarding base and re-programs the network to ensure that traffic keeps moving from/to the end hosts of the network. However, it may take time for the controller to receive the information that a switch is not operational, which can lead to a service interruption in the network.